1. Field of the Invention
The present invention relates to a rear projector for projecting an image form a rear side of a screen by using a plurality of image display panels.
2. Description of the Related Art
In recent years, a rear projection television draws attention as a large-sized display device. The rear projection television is constituted of a screen built in a housing, a plane mirror disposed behind the screen, and a projector engine (main component of projector) for emitting projection light toward the plane mirror. The projector engine is provided with an illumination optical system, image display panels and a projection optical system. The illumination optical system produces uniform illumination light from the light of a high-intensity light source. The image display panels form an original image by modulating the illumination light. The projection optical system enlarges and radiates the projection light to which image information is given by the image display panels.
The projector engine is generally disposed at a position where the projection light is upwardly radiated toward the plane mirror inclined relative to the screen and placed at the rear side thereof. As to the rear projection television, a depth of the housing is reduced by standing the plane mirror as parallel as possible with a surface of the screen so as to hold down an inclination angle of the plane mirror rather than 45 degrees. Therefore, the projector engine is built in such as to confront the plane mirror and such as to radiate the projection light in an oblique-and-upward direction(see Japanese Patent Laid-Open Publication No. 2002-141025, for instance).
A conventional rear projector, however, employs a projector engine in which radiating directions of the illumination light and the projection light are parallel. Thus, there arises a problem in that a size increases in a depth direction. For example, when the conventional projector engine is horizontally placed to lead the projection light to the screen along a Z-shaped optical path formed by using two plane mirrors, the whole length of the projector engine is long in spite of holding down the inclinations of the plane mirrors. Due to this, it is necessary to redundantly secure the depth size of the housing.